To avoid the disadvantages inherent in the use of hypochlorite solutions in household laundry bleach, disinfectants, hard surface cleansers, and other cleaning compositions, manufacturers of these products have developed alternatives based on acidic aqueous hydrogen peroxide compositions. Hydrogen peroxide is generally acceptable from a toxicological and environmental standpoint because its decomposition products are oxygen and water. In addition, these compositions are also fiber-safe and color-safe.
Decomposition of hydrogen peroxide caused by catalytically active substances, such as metal ions, is extremely difficult to prevent. For products that contain hydrogen peroxide to be effective, a substantial proportion of the hydrogen peroxide must survive between manufacture and use. In addition, decomposition produces oxygen gas, which could overpressure the container and cause it to rupture during storage or shipping. Therefore, these compositions typically contain stabilizers to prevent decomposition of the hydrogen peroxide. For example, tin compounds, such as sodium stannate, and phosphorus based chelating agent, have been used as stabilizers for acidic compositions (i.e., those with a pH less than about 5).
Because an alkaline environment is normally required for cleaning efficiency, the performance of hydrogen peroxide containing cleaning compositions can be improved by formulating alkaline products. However, the commercial use of alkaline formulations has been hindered by the strong tendency of alkaline hydrogen peroxide compositions to decompose during storage. In addition, under typical storage conditions, decomposition may produce hydroxide ions, which increase the pH and, thus, further increase the decomposition rate. With excessive decomposition of the hydrogen peroxide, the composition loses its cleaning ability.
Various stabilizers have been developed to improve the stability of aqueous alkaline hydrogen peroxide compositions. These are disclosed, for example, in Woerner, U.S. Pat. Pub. 2003/0073150 A1; Steiner, U.S. Pat. No. 5,736,497; Lanniel, U.S. Pat. No. 5,102,575; Smith, U.S. Pat. No.4,525,291; and Kowalski, U.S. Pat. No. 4,294,575. However, these stabilizers are not totally satisfactory. Thus, a need exists for aqueous alkaline hydrogen peroxide compositions with increased stability.